[coreboot-gerrit] New patch to review for coreboot: 83dccf2 broadwell: Preserve VbNv around cmos_init

[Stefan Reinauer]

Stefan Reinauer ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9495

-gerrit

commit 83dccf2e9343283f7df9077534988a207a9275f8
Author: Duncan Laurie 
Date:   Sun Jan 18 14:06:42 2015 -0800

broadwell: Preserve VbNv around cmos_init

To ensure that boot flags (legacy, usb, signed-only) are
    properly restored from CMOS and used in the first boot after
    a battery removal or RTC reset then the VbNv region needs to
    be preserved around the cmos_init call.

When using vboot firmware selection and VbNv is stored in CMOS
    then that region of CMOS will have been re-initialized by the
    time we call cmos_init and reset CMOS if the chipset flag was
    set indicating a problem.

BUG=chrome-os-partner:35240
    BRANCH=broadwell
    TEST=manual testing on samus:
    1) boot in dev mode, enable dev_boot_legacy and ensure it works
    2) on EC console pulse PCH_RTCRST_L low for a second
    3) ensure first boot after RTC reset will still boot legacy mode
    4) remove battery for a time
    5) ensure first boot after battery is re-inserted will still
    boot legacy mode

Change-Id: Ica256bbdcba6d4616957ff38e63914dd15f645c6
    Signed-off-by: Stefan Reinauer 
    Original-Commit-Id: 881c7841c95dec392a66eef38a7112c1f385fdfa
    Original-Change-Id: I4c33f183ba4b301d68ae31c41fc6663f3be857b0
    Original-Signed-off-by: Duncan Laurie 
    Original-Reviewed-on: https://chromium-review.googlesource.com/241529
    Original-Reviewed-by: Aaron Durbin 
---
 src/soc/intel/broadwell/lpc.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/soc/intel/broadwell/lpc.c b/src/soc/intel/broadwell/lpc.c
index 6ebc758..9a4c65c 100644
--- a/src/soc/intel/broadwell/lpc.c
+++ b/src/soc/intel/broadwell/lpc.c
@@ -49,6 +49,10 @@
 #include <arch/acpigen.h>
 #include <cpu/cpu.h>

+#if IS_ENABLED(CONFIG_CHROMEOS)
+#include <vendorcode/google/chromeos/chromeos.h>
+#endif
+
 static void pch_enable_ioapic(struct device *dev)
 {
    u32 reg32;
@@ -174,6 +178,25 @@ static void pch_power_options(device_t dev)
    enable_alt_smi(config->alt_gp_smi_en);
 }

+#if IS_ENABLED(CONFIG_CHROMEOS_VBNV_CMOS)
+/*
+ * Preserve Vboot NV data when clearing CMOS as it will
+ * have been re-initialized already by Vboot firmware init.
+ */
+static void pch_cmos_init_preserve(int reset)
+{
+	uint8_t vbnv[CONFIG_VBNV_SIZE];
+
+	if (reset)
+		read_vbnv(vbnv);
+
+	cmos_init(reset);
+
+	if (reset)
+		save_vbnv(vbnv);
+}
+#endif
+
 static void pch_rtc_init(struct device *dev)
 {
    u8 reg8;
@@ -187,7 +210,11 @@ static void pch_rtc_init(struct device *dev)
    	printk(BIOS_DEBUG, "rtc_failed = 0x%x\n", rtc_failed);
    }

+#if IS_ENABLED(CONFIG_CHROMEOS_VBNV_CMOS)
+	pch_cmos_init_preserve(rtc_failed);
+#else
    cmos_init(rtc_failed);
+#endif
 }

static const struct reg_script pch_misc_init_script[] = {